There are quite a few, from Kochi, Andaman, Lakshdweep, Bramhaputra and sunderban cruises to a longer cruise on Ganges which covers Delh-Agra-Jaipur with partial stay in hotels and partial on board.
There are many places in India which offers cruise experience:
1. The Golden Triangle Cruise : The trip starts from New Delhi to Kolkata along the heritage sites into the sacred Ganges.
2. Cochi : the most popular beach cruise destination in India.
3. Andaman
4. Dibru-Saikhowa River Cruise
5. Brahmaputra River Cruise
6. Sunderbans Boat Cruise
7. Kerala Backwater Cruise
8. Ganges River Cruise
There are many cruise options in Andaman. You can get the not so luxurious ones at a cheap cost. I tried the Macruzz when I was there, and it was really cool.